Indian Patents. 213810:"A PROCESS FOR PREPARING A NEUROTROPIC LOW MOLECULAR WEIGHT HETEROCYCLIC COMPOUND"

Title of Invention	"A PROCESS FOR PREPARING A NEUROTROPIC LOW MOLECULAR WEIGHT HETEROCYCLIC COMPOUND"
Abstract	This invention relates to neurotrophic low molecular weight, small molecule heterocyclic esters and amides having an affinity for FKBP-type immunophilins, and their use as inhibitors of the enzyme activity associated with immunophilin proteins, particularly peptidyl-prolyl isomerase, or rotamase, enzyme activity.

Full Text	I~munophilins were originally discovered and studied ir. the immune tissue. It was initially postulated by these skilled in the art that inhibition of the uncphiiins' rotamase activity leads to inhibition of. 7-ceil proliferation, thereby causing the immunesuppressive activity exhibited by immunosupcressant drugs, such as cyclcspcrin A, FX506 and rapamycin. Further study has shewn that the inhibition of rotamase activity, in and cf itself, does not result in i~muncsuppressive activity. Schreiber et al., Science, 1390, vol. 25C, pp. 55c-553. Instead, immunosuppression appears to stem from the. formulation of a complex of irnmuncsuppressar.t drugs and irnmuncphilins. It has been shown that the i-muncphilin-drug complexes interact with ternary protein targets,, as their mode of action. Schreiber et al. , Call, 19S1, vol. 56, pp. 807-815. In the case of FK3F-FK506 and cyclophilin-CsA, the iT.muncchilin-drug complexes bind to the enzyme calcineurin and inhibit the T-cell receptor signalling which leads to T-cell proliferation. Similarly, the immunophj-lin-drug complex of FK3P-rapamycin interacts with the RAFT1/FRA? protein and inhibits the IL-2 receptor signalling. Immunophilins have been found to be present at high concentrations in the central nervous system. Immunochilins are enriched 1.0-50 times more in the central nervous system tnan in the immune system. Within neural tissues, immunophilins appear to influence nitric oxide synthesis, neurotransmitter release and neurcnal process extension. It has been found that picomolar concentrations cf an immunosuppressant such as FK5Q6 and rapamycin stimulate neurite outgrowth in PC12 cells and sensory neurons, namely dorsal root ganglion cells (DRGs) . Lyons et al., Proc. of Nad. Acad. Sci., 1994, vol. 91, pp. 3191-3195. In whole animal experiments, FX506 has been shown to stimulate nerve regeneration following facial -nerve injury.' Surprisingly, it has been found that certain compounds with a high affinity for FKBPs are potent rotamase inhibitors and exhibit excellent neurotrcphic effects. Furthermore, these rotamase inhibitors are devoid of immunosuppressive activity. These findings suggest the use of rotamase inhibitors in treating various peripheral neuropathies and enhancing neuronal regrowth in the central nervous system (CNS). Studies have demonstrated that neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis (ALS) may occur due to the loss, or decreased availability, of a neurotrophic substance specific: for a particular population of neurons affected in the disorder. Several ' neurotrcphic factors affecting specific neuronai populations in the central nervous system have been identified. For example, it has been hypothesized that Alzheimer's disease results from a decrease or loss of nerve growth factor (NGF). It has thus been proposed to treat SDAT patients with exogenous nerve growth factor or other neurotrophic proteins, such as brain derived growth factor, glial derived growth factor, ciliary neurotrcphic factor and neurotrcpin-3, to increase the survival of degenerating neuronai populations. Clinical application of these proteins in various neurological disease states is hampered by difficulties in the delivery and bioavailability of large proteins to nervous system targets. By contrast, immunosuppressant drugs with neurotrophic activity are relatively small and display excellent bioavailability and specificity. However, when administered chronically, immunosuppressant drugs exhibit a number of potentially serious side effects including nephrotoxicity, such as impairment of glomerular filtration and irreversible interstitial fibrosis (Kopp et al. , tremors, or non-specific cerebral angina, such as non-localized headaches (De Groen et al., N. Engl. J. Med., 1987, 317:861.); and vascular hypertension with complications resulting therefrom (Kahan et al. , N. Engl. In order tc prevent the side effects associated with use of the irr.r.unc suppressant compounds, the present invention provides ncn-immunosuppressive compounds containing small molecule FK3P rotamase inhibitors for enhancing neurite outgrowth, and promoting neurcnal growth and regeneration in various neuropathoiogical situations where neuronal repair can be facilitated, including: peripheral nerve damage caused by physical injury or disease state such as diabetes; physical damage to the central nervous system (spinal cord and brain); brain damage, associated with stroke; and neurological disorders relating to neurodegeneration, such as Parkinson's disease, SDA7 (Alzheimer's disease), and amyo.trophic lateral sclerosis. SUMMARY OF THE INVENTION The present invention relates tc neurotrophic low molecular weight, small molecule compounds having an affinity for FKB?-type immunophilins. Once bound to these proteins, the neurctrophic compounds are potent inhibitors of the enzyme activity associated with immunophilin proteins, particularly peptidyl-prolyl isomerase, or rctamase, enzyme activity. A key feature of the compounds cf the present invention is that they do not exert any significant immunosuppressive activity in addition to their neurotropic activity. Specifically, the present invention relates to a process for preparing a neurotropic low molecular weight heterocyclic compound of formula I (Formula Removed) or a pharmaceutically acceptable salt thereof, wherein: A and B, together with the nitrogen and carbon atoms to which they are respectively attached form a 5-7 membered saturated or unsaturated heterocyclic ring containing at least one additional O, S, SO, SO2 NH or NR] heteroatom in any chemically stable oxidation state; X is O or S; ZisO,NHorNRi; W and Y are independently O; RI is - Ci - Ce straight or branched chain alkyl, which is substituted in one or more position(s) with (AijX, - Cz - Ce straight or branched chain alkenyl, which is substituted in one or more positions with (Ar^, €3 - Cg cycloalkyl., €3 - Cg cycloalkyl connected by a Q - Cg straight or branched chain alkyl or alkenyl, or n is 1 or 2; RI is - Ci - Cg straight or branched chain alkyl, Ca - Ce straight or branched chain alkenyl, Cs-Cg cycloalkyl, Cs - C? cycloalkenyl or - Ar,; wherein said alkyl, alkenyl, cycloalkyi or cycloalkenyl is either unsubstituted or substituted in one or more position(s) with Ci - C4 straight or branched chain alkyl, Ca - C4 straight or branched chain alkenyl, hydroxyl or a combination thereof; and Art and Ar2 are independently : a monocyclic carbocyclic ring, a bicyclic carbocyclic ring a tricyclic carbocyclic ring, a monocyclic heterocyclic ring, a bicyclic heterocyclic ring, or a tricyclic heterocyclic ring, wherein the ring is either unsubstituted or substituted in one to three positions with halo, hydroxyl, nitro, triflouromethyl, Ci - Ce straight or branched chain alkyl or alkenyl, Ca - Ce straight or branched chain alkyl or alkenyl, Ci - C4 alkoxy, Ci - C4 alkenyloxy, phenoxy, ^ - benzyloxy, amino or a combinationrthereof; wherein the individual ring sizes are 5-6 members; and wjierein the heterocyclic ring contains 1 - 6 heteroatom(s) selected fi-om the group consisting'bf §, N, S, and a combination thereof. which process comprises the steps : (a) reacting jn a manner described herein a compound of Formula (la) (Formula Removed) wherein A and B are defined above, V is a halogen and R is an alkyl to obtain an intermediate compound of formula (le) wherein Rj is H; (Formula Removed) R2 (b): reacting a compound of formula (le) with a compound of formulai(lc): (Formula Removed) wherein Z and RI are as defined above and (c ) : reacting the product of step (b) with a compound of formula (Id): (Formula Removed) wherein R2 is as defined above to obtain a compound of formula I. A preferred embodiment of this invention is a compound of formula H: (Formula Removed) cr a pharmaceutically acceptable salt thereof, wherein: A, B and C are independently CH2, 0, S, SO, SO2, NH cr NR,; RI is C-C5 straight cr branched chain alkyl cr aikenyi, which is substituted in one or more position(s) with (ArJ.,, (Ar:;_ connected by a CX-C6 straight cr branched chain alkyl cr aikenyl, or a combination thereof,- n is 1 or 2 ; R2 is either C-CS straight or branched chain alkyi cr aikenyl, C3-C8 cycloalkyl, CS-C7 cycloalkenyl, or Ar^; and Ar.^ is a mono-, bi- or tricyclic, carbo- cr heterocyclic ring, wherein the ring is either unsubstituted or substituted in one to three position(s) with halo, hydrcxyl, nitro, trifluoromethyl, C-C6 straight or branched chain alkyl or aikenyl, CT-C4 alkoxy, C-C^ alkenylcxy, phenoxy, benzyloxy, amino, or a combination thereof; wherein the individual ring sizes are 5-6 members; and wherein the heterocyclic ring contains 1-6 heteroatom(s) selected from the group consisting of 0, N, S, and a combination thereof. Another preferred embodiment is a compound of (Formula Removed) cr a pharrnaceutically acceptable salt thereof, wherein: A, B, C and. D are independently CH2, O, S, SO, SO,, NH cr NR;; R: is C-Cc straight or branched chain alkyl or alkenyi, which is substituted in one or more position(s) with (ArO,, (ArJ. connected by a C-C6 straight or branched chain alkyl cr alkenyi, or a combination thereof; n is '-. cr^2; R, is either C-C9 straight or branched chain alkyi or alkenyi., C, -C8 cycioalkyl, C5-C7 cycloalkenyl, or Ar17-and Ar: is a mono-, bi- or tricyclic, carbo- or heterccyclic ring, wherein the ring is either unsubstituted or substituted in one to three position(s) with halo, hydroxyl, nitro, trifluoromethyl, Ci-Cg straight or branched chain alkyl or alkenyi, C^-C, alkoxy, C-C, alkenyloxy, phenoxy, benzyloxy, amino, or a combination thereof; wherein the individual ring sizes are 5-6 members; and wherein the heterocyclic ring contains' 1-6 heteroatom(s) selected from the grou^ consisting of O, N, S, and a combination thereof. The present invention aisc relates to a pharmaceutical composition comprising a neurotrophically effective amount of. the compound of formula I, II or III, and a pharrnaceutically acceptable carrier. The present: invention further relates to a method of effecting a neuronal activity in an animal, comprising: administering to the animal a neurotrophically effective amount: of the compound of formula I, II or III. BRIEF DESCRIPTION OF THE DRAWINGS FIG. I (A) is a representative photomicrograph of compound I (1 pM) promoting neurite outgrowth in sensory neurons. FIG. I(B) is a representative photomicrograph of compound I (10 pM) promoting neurite outgrowth in sensory neurons. FIG. 1 (C) is a representative photomicrograph of c compound 1 (100 pM) promoting neurite outgrowth in sensory neurons. FIG. 2 (A) is a representative photomicrograph of compound 2 (10 pM) promoting neurite outgrowth in sensory neurons. FIG. 2(3) is a representative photomicrograph of compound 2 (100 pM) promoting neurite outgrowth in sensory neurons. FIG. 2(C! is a representative photomicrograph of compound 2 (10 riM) promoting neurite outgrowth in sensorv neurons. DETAILED DESCRIPTION OF THE INVENTION Definitions "Alkyl" means a" branched or unbranched saturated hydrocarbon chair, containing 1 to 6 carbon atoms, such as methyl, ethyl, propyl, iso-propyl, "butyl, iso-butyl, tert-butyl, n-pentyl, n-hexyl, and the like, unless otherwise indicated. "Alkoxy" means the group -OR wherein R is alkyl as herein defined.. Preferably, R is a branched or unbranched saturated hydrocarbon chain containing 1 to 3 carbon atoms. "Halo" means fluoro, chloro, bromo, or iodc, unless otherwise indicated. "Phenyl" includes all possible isomeric phenyl radicals, optionally monosubstituted or multi-substituted with substituents selected from the group consisting of alkyl, alkoxy, hydroxy, halo, and haloalkyl. The term "pharmaceutically acceptable salt" refers to- salts of t±ie subject compounds which posses the desired pharmacological activity and which are neither biologically r.cr otherwise undesirable. The salts can be formed with ir.orga.iic acids such as acetate, adipate, aiginate, aspartate, benzoate, benzenesulfonate, bisulfate butyrate, citrate, camphorate, camphorsulfcnate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesuIronate, fumarate, glucoheptancate, glycercphosphate, hemisulfate heptar.oate, hexar.cate, hydrochloride hydrobromide, hydrcicdide, 2-hydroxyethanesulfonate , lactate, maleate, methanesulfcnate, 2-naphthalenesulfonate, nicotinate, oxaiate, thiocyanate, tosylate and undecanoate. Base salts include ammonium salts, alkali metal salts such as sodium and potassium salts, alkaline earth metal salts such as calcium and magne'sium salts, salt with organic bases such as dicyclohexylamine salts, N-methyl-D-glucamine, and salts with amino acids such as arginine, lysine, and so forth. - Also, the basic nitrogen-containing groups can be quartemized with such agents as lower alkyl haiides, such as methyl, ethyl, propyl, and cbutyl chloride, bromides and iodides,-' dialkyl sulfates like dimethyl, diethyl, dibutyl and diamyl sulfates, long chain haiides such as decyl, lauryl, myristyl and stearyl chlorides, bromides and iodides, aralkyl haiides like benzyl and phenethyi bromides and others. Water or oil-soluble or dispersibie products are thereby obtained. The compounds of this invention possess asymmetric centers and thus can be produced as mixtures of stereoiscmers or as individual stereoisomers. The individual stereoiscmers may be obtained by using an optically ac~ive; starring material, by resolving a racemic or ncn-racemic mixture of an intermediate at some appropriate stage of the synthesis, or by resolution of the compound of formula -, I) . It is understood that the individual stereoiscmers as well as mixtures (racemic and non-racemic) of stereoisomers are encompassed by the scope of the present invention. The compounds of this invention possess at least one asymmetric centers and thus can be produced as mixtures of stereoiscmers or as individual R- and S-s~ereoisomers. The individual enantiomers may be obtained by resolving a racemic or non-racemic mixture of an intermediate at some appropriate stage of the synthesis. It is understood that the individual R- and S- stereoisomers as well as mixtures of stereoisomers are encompassed by this invention. The S-stereoisomer is most preferred due to its greater c activity. "Iscmers" are different compounds that have the same molecular formula. "Stereoisomers" are isomers that differ only in the way the atoms are arranged in space. "Enantiomers" are a pair of stersoisomers that are nor.-superimposable mirror images of each ether. "Diastereoiscmers" are stereoiscmers which are net rr.irrcr images of each ether. "Racemic mixture" means a mixture containing equal parts of individual enantiomers. "Ncn-racemic mixture" is a mixture containing unequal parts of individual enantiomers or sterecisomers. The term "treatment" as used herein covers any treatment of a disease and/or condition in an animal, particularly a human, and includes: (i) preventing a disease and/or condition from occurring in a subject which may be predisposed to the disease and/or condition but has not yet been diagnosed as having it; •;ii) inhibiting the disease and/or condition, i.e. , arresting its development; or (iii) relieving the disease and/or condition, i.e. , causing regression of the disease and/or, condition. The system used in naming the compounds of the present invention is shown below, using a compound of formula II as an example. A compound of formula II wherein A is CH2, B is S, C is CH2, RT is 3-phenylpropyl and R2 is 3,3-dimethylpentyl, is named 3-phenyl-l-propyl(2S}-1-(3,3-dimethyl-l, 2-dicxcpencyl) -2- (4-thiazolidine) carboxylate . Compounds of the Invention The neurotrophic low molecular weiqht, small molecule FKBP inhibitor compounds of .this invention have an affinity for FKBP-type immunophilins, such as FKBP12. When the neurotrophic compounds of this invention are bound to an ?K3?~type irr.ir.unophilin, they have been found to inhibit the prolyl-peptidyl cis-trans isomerase activity, or rotamase, activity of the binding protein ana unexpectedly stimulate neurite growth. FORMULA I In particular, this invention relates to a compound of formula I: (Formula Removed) or a pharmaceutically acceptable salt thereof, wherein: A and B, together with the nitrogen and carbon atoms to which they are respectively attached, form a 5-7 membered saturated or unsaturated heterocyclic ring containing, in addition to the nitrogen atom, at least one additional O, S, SC, SC-, NH or NR, heteroatom in any chemically stable oxidation state,- X is O or S; 2 is 0, NH or NR-_; W and Y are independently O, S, CH2 or K2; R: is C-CS straight or branched chain alkyi or aikenyl, which is substituted in one or more position(s) with 'Ar:}n, (Ar^. connected by a C-CS straight or branched chain aikyl or alkenyi, C3-C3 cycloalkyl, C3-C8 cycloaikyi connected by a C-_-Cs straight or branched chain aikyl or alkenyi, Ar2/ or a corr-bination thereof; n is 1 or 2; Rn is either C-C5 straight or branched chain aikyl or aikenyl, C3-CS cycicalkyl, CS-C- cycloalkenyl, or Ar,, wherein said aikyl, -aikenyl, cycloalkyl or cycloalkenyl is either unsubstituted cr substituted in one or more position(s) with C-C4 straight or branched chain aikyl or alkenyi, hydroxyi, cr a combination thereof; and Ar. and Ar2 are independently a mono-, bi- or tricyciic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted in one to three position(s) with halo, hydroxyi, nitro, trifluoromethyl, C-Cg straight or branched chain aikyl or aikenyl, C^-C^ alkoxy, C-C4 alkenyioxy, phenoxy, benzyloxy, amino, or a combination thereof; wherein the individual ring sizes are 5-6 members; and wherein the heterocyclic ringcontains 1-6 heteroatom(s) selected from the group consisting cf C, N, S, and a combination thereof. The mcnc- and bicyciic, carbo- and heterocyclic rings include without limitation naphchyl, indolyl, furyl, thiazclyl, chienyl, pyridyl, quinolinyl, iscquinoiinyl, flucrenyl and phenyl. FORMULA II A preferred embodiment of this invention is a cornoound of formula II: (Formula Removed) cr a pharmaceutically acceptable salt thereof, wherein: A, B and C are independently CH2, O, S, SO, SO2/ NH cr NRI; RI is Ci-Cc straight or branched chain alkyl or alkenyl, which is substituted in one or more position(s) with (ArJn, (Ar:)n connected by a C^-Cg straight or branched chain alkyl or alkenyl, or a combination thereof; nisi or .2 ; R: is either C,-C9 straight or branched chain alkyl cr aikenyl, C,-CS cycloaikyl, CS-C, cycloalkenyl, or Ar, ; and Ar. is a mono-, bi- cr tricyclic, carbo- or heterccyciic ring, wherein the ring is either unsubstituted cr substituted in one to three position(s) with hale, hydrcxyl, nitre, trifluoromethyl, C-CS straight or branched chain alkyl or aikenyl, C,_-C4 alkcxy, C:-C4 alkenyloxy, phencxy, benzyloxy, amino, or a combination thereof; wherein the individual ring sizes are 5-6 members; and wherein the heterocyclic ring contains 1-6 -heteroatcm(s) selected from the group consisting of C, N, S, and a combination thereof. In a oarticularly preferred embodiment of formula II compounds: (Formula Removed) R, is selected from the group consisting of 3-phenyipropyl and 3 -(3-pyridyi)propyl; and R2 is selected from the group consisting of 3,3-dimethylpentyi, cyclohexyl, and tert-butyl. Specific exemplifications of this embodiment are presented in TABUS I. TABLE I (Table Removed) FORMULA III Another preferred embodiment of this invention is a comoound of formula III: (Formula Removed) or a pharmaceutically acceptable salt thereof, wherein: A, B, C and D are independently CH2/ O, S, SO, SO2, NK or NRZ; j ^ is C-CS straight or branched chain alkyl or alkenyl, which is substituted in one or more position(s) with (ArO., (Ar,), connected by a C-CS straight or branched chain aikyl cr aikenyl, or a combination thereof; n is 1 or 2; R2 is either C-C9 straight or branched chain aikyl or aikenyl, C,-C3 cycioalkyl, C5-CT cycloalkenyl, or Arx; and Ar1 is a mono-, bi- cr tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted cr substituted in one to three position(s) with halo, hydroxyl, nitro, trifluoromethyl, Q-Cg straig-ht or branched chain aikyl or aikenyl, C,_-C4 alkoxy, C-C4 aikenyloxy, phencxy, benzyloxy, araino, or a combination thereof; wherein the individual ring sizes are 5-6 members; and wherein the heterocyclic ring contains 1-6 .heteroacom(s) selected from the group consisting of 0, N, S, and a combination thereof. In a particularly preferred embodiment of formula III compounds: A is CK2; B is CH2; C is S, O or NH; D is CH2; R., is selected from the group consisting of 3-^i am^ /0 , 4 , 5-trimethcxy) phenylpropyl; and R2 is selected from the group consisting of 3,3-dimethylper.tyl, cyclohexyl, 3-3-dimethylpropyl, phenyl, and 3,4,5 -trimethoxyphenyl. Specific exemplifications of this embodiment are cresented in TABLE II. TABLE (Table Removed) The compounds of the present invention exist as stereoisomeric forms, either enantiomers or diasterecisomers. Included within the scope of the invention are the enantiomers, the racemic form, and c diastereoiscmeric mixtures. Enantiomers and ddastereois-omers can be separated by methods known to those -skitied in the art. Methods of Using the Compounds of the Invention The compounds of the present invention have an affinity for the FK506 binding protein, particularly FK3PI2, which is present in the brain. When the inventive compounds bind to FK3P in the brain, they exhibit excellent neurotrophic activity. This activity is useful in the stimulation of damaged neurons, the promotion of neuronai regeneration, the prevention of neurodegeneration, and the treatment of several neurological disorders known to be associated with neuronai degeneration and peripheral neuropathies. For the foregoing reasons, the present invention further relates to a method of effecting a neuronai activity in an animal, comprising.- administering to the animal a neurotrophically effective amount of a compound of formula I, II or III. In a preferred embodiment, .the neuronai activity is selected from the group consisting of stimulation of damaged neurons, promotion of neuronai regeneration, prevention of neurodegeneration and treatment of neurological disorder. * The neurological disorders that may be treated include but are not limited to: trigeminal neuralgia; glossopharyngeal neuralgia; Bell's Palsy; myasthenia gravis,- muscular dystrophy,- amyotrophic lateral sclerosis; progressive muscular atrophy; progressive bulbar inherited muscular atrophy; hemiated; ruptured or prolapsed invertabrae disk syndromes; cervical spcndylosis,- plexus disorders; thoracic outlet destruction syndromes; peripheral neuropathic such as those caused by lead, dapsone, ticks, porphyria, or Gullain-Barre syndrome; Alzheimer's disease; and Parkinson's disease. The compounds of the present invention are particularly useful for treating a neurological disorder selected from the group consisting of: peripheral neuropathy caused by physical injury or disease state, physical damage to the brain, physical damage to the spinal cord, stroke associated with brain damage, and neurological disorder relating to neurodegeneration. Examples of neurological disorders relating to neurodegeneration are Alzheimer's Disease, Parkinson's Disease, and amyotrophic lateral sclerosis. For these purposes the compounds of the present invention may be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an implanted reservoir in dosage formulations - containing conventional non-toxic pharmaceutically-acceptable carriers, adjuvants and vehicles. The term parenteral as used herein includes subcutaneous, intravenous, intramuscular, intraperitoneally, intrathecally, intraventricularly, intrasternal and intracraniai injection or infusion techniques. To be effective therapeuticaliy as central nervous system targets, the compounds of the present invention should readily penetrate the blood-brain barrier when peripherally administered. Compounds which cannot penetrate the blood-brain barrier can be effectively administered by an intraventricular route. The compounds of ..the present invention may be administered in the form of sterile injectable preparations, for example, as sterile injectable aqueous or oleaginous suspensions. These suspensions may be formulated according to techniques known in the art using s.uitable dispersing or wetting agents and suspending -! \|f agents. The sterile injectable preparations may also be sterile injectable solutions or suspensions in non-toxic parenteraliy-acceptable diluents or solvents, for example, as solutions in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride c solution. .In addition, sterile, fixed oils are conventionally employed as solvents or suspending mediums. For. this purpose, any bland fixed oil may be employed including synthetic mono- or di-glycerides. Fatty acids such as oleic acid and its glyceride derivatives, including olive oil and castor oil, especially in their polyoxyethylated versions, are useful in the preparation of injectables. These-oil solutions or suspensions ~ay also contain long-chain alcohol diluents or dispersa-nts . The compounds may be administered orally in the form of capsules, tablets, aqueous suspensions or solutions. Tablets may contain carriers such as lactose and corn starch, and/or lubricating, agents such as magnesium stearate. Capsules may contain diluents including lactose and dried corn starch. Aqueous suspensions may contain emulsifying and suspending agents combined with the active ingredient. The oral dosage forms may further contain sweetening and/or flavoring and/or coloring agents. The compounds of this invention may also be administered rsctaliy in the form of suppositories. These compositions can be prepared by mixing the drug with a suitable non-irritating excipient which is solid at room temperature, but liquid at rectal temperature and, therefore, will melt in the rectum to release the drug. Such materials "include cocoa butter, beeswax and polyethylene glycols. The compounds of this invention may also be administered topically, especially when the conditions addressed for treatment involve areas or organs readily accessible by topical application, including neurological disorders of the eye, the skin, or the lower intestinal tract. Suitable topical formulations are readily prepared for each of these areas. For topical application to the eye, or ophthalmic use, the compounds can be formulated as micronized suspensions in isotcnic, pH adjusted sterile saline, or, preferably, as solutions in isctonic, pH adjusted sterile saline, either with or without a preservative such as benzyialkonium chloride. Alternatively for the ophthalmic uses the compounds may be formulated in an ointment such as petrolatum. For topical application to the skin, the compounds can be formulated in a suitable ointment containing the compound suspended or dissolved in, for example, a mixture with one or more of the following: mineral oil, liquid petrolatum, white petrolatum, propylene giycol, polyoxyethylene polyoxypropylene compound, emulsifying wax and water. Alternatively, the compounds can be formulated in a suitable lotion or cream containing the active compound suspended or dissolved in, for example, c a mixture of one or more of the following: mineral oil, sorbitan monostearate, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water. Topical application for the lower intestinal tract an"be-effected. iri a rectal suppository formulation (see above) cr in a suitable enema formulation. Dcsage levels on the order cf about 0.1 mg to about 10,COO mg cf the active ingredient compound are useful in the treatment of the above conditions, with preferred levels cf about 0.1 mg to about 1,000 mg. The amount of active ingredient that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. It is understood, however, that a specific dose level for any particular patient will depend upon a variety cf factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time cf administration, rate of excretion, drug combination, and the severity of the particular disease being treated and form cf administration. The compounds can be administered with other neurctrophic agents such as neurctrophic growth factor (NG?), giial derived growth factor, brain derived growth factor, ciliary neurotrophic factor, and neurotropin-3. c The dosage level of other neurotrophic drugs will depend upon the factors previously stated and the neurotrophic effectiveness of the drug combination. Pharmaceutical: Compositions of the Invention The present: invention also relates to a pharmaceutical composition comprising: (i) a neurotrophically effective amount of the compound of formula I, II or III, and (ii) a pharmaceutically acceptable carrier. The above discussion relating to the utility and administration of the compounds of the present invention also applies to the pharmaceutical compositions of the present invention. Examples The following examples are illustrative of the present invention and are not intended to be limitations thereon. Unless otherwise specified, all percentages are based on 100% by weight of the final compound. EXAMPLE 1 Synthesis of 3-phenyl-l-.pr.opyl (2S) -1- (3 , 3-d-imethvl-1, 2-dioxopentyl) -2- (4-thia2olidine) carboxvlate {1) •« 1- (1, 2 -dioxo-2 -me-thoxve.thvl) 2 - (4 -thiazolidine) -carboxylate. A solution of L-thioproline (1.51 g; 11.34 mmol) in 40 mL of dry methylene chloride was cooled to 0°C and treated with 3.3 mL (2.41 g; 23,81 mmol) of * triethylamine.' After stirring this mixture for 30 minutes, a solution of methyl oxalyl chloride (1.81 g; 14.74 mmol) was added dropwise. The resulting mixture was stirred at 0°C for 1.5 hours, filtered through Celite to remove solids, dried and concentrated. The crude material was purified on a silic gel column, eluting with 10% MeCH in methylene chloride, to obtain 2.0 g of the cxamate as an orange-yellow solid. 3 -chenvl-1 -proovl (253 -1 - (1, 2 -dioxo-2-methoxyethyl) 2 -(4 -thiazolidine)carboxvlate. 1- (1,2-dioxo-2 -rnethcxyethyi) 2- (4-thiazolidine) carboxylate (500 mg; 2.25 mmol}, 3-phenyl-1-propanol (465 mg; 3.42 mmol), dicyciohexylcarbodiimide • (750 mg; 3.65 mmol), 4-dimethyiamincpyridine (95 mg; 0.75 mmol) and camphcrsulfcnic acid (175 mg; 0.75 mmol) in 30 mL of methylene chloride were stirred together overnight. The mixture was filtered through Celite to remove solids" and chromatcgrapheg (25% ethyl acetane/hexane) to obtain 690 mg of material, ZH NMR (CDC13, 300 MHz) : 51.92-2.01 (m, 2H); 2.61-2.69 (m, 2H); 3-34 (m, 1H) ; 4.11-4.25 (m, 2H); 4.73 (m, IK); 5.34 (m, 1H) ; 7.12 (m, 3H) ; 7.23 (m, 2H)„ 3 - ohe nv 1 - 1 - P r.op v 1 (25? - 1 - (3 , 3 - d i me t hy 1 - 1 , 2 -dioxopentvl)-2-(4-thiazolidine)carboxvlate (1) . A solution of 3-phenyl-l-prcpyl(25)-1-(1,2-dioxo-2- methoxyethyl) 2-(4-thiazolidine) carboxylate (670 mg; 1.98 mmol) in tetrahydrofuran (10 mL) was cooled to -78°C and treated with 2.3 mL of a 1.0 M solution of 1,1-dimethylpropylmagnesium chloride in ether. After stirring the mixture for 3 hours, it was poured into saturated ammonium chloride, extracted into ethyl acetate, and the organic phase was washed with water, dried and concentrated. The crude material was purified on a silica gel colun^n, eiuting with 25% ethyl acetate in hexane, to obtain 3SG mg of the compound of Example 1 as a yellow oil, LK NMR (CDC1,, 300 iMHz) : d 0.86 (t, 3H) ; 1.21 (s, 3H); 1.26 is, 3H); 1.S2-1.91 (m, 3H); 2.01 (m, 2K) ; 2.71 (m/ 2K) ; 2.26-3.23 (m, 2K) ; 4.19 (m, 2K) ; 4.58 (m, IK); 7.19 (m, 3H) ; 7.30 (m, 2H) . Anal. Clcd. for C20H27NC.S: C, 63.63; H, 7.23; N, 3.71. Found: C, 64.29; H, 7.35; N, 3.46. EXAMPLE 2 Synthesis of 3 - (3-pyridyl) -1-propvl (23} -.1- (3/3 -dimethyl- 1, 2-dioxopentvl) -2- (4-thiazolidine) ^carboxylaite {2} - The compound of Example 2 was prepared according to the procedure of Example 1, using 3 -(3-pyridyl)-1-propancl in the final step, to yield 3-(3-pyridyl)-1-propyi(25) -1- (3 , 3-dimethyl -1,2-dioxopentyl) -2 - (4-thiazolidine) carboxy late,. -H NMR (CDC13, 300 MHz):- 6 0.89 (t, 3H, J=7.3); 1.25 (s, 3H) ; 1.28 (s, 3H) ; 1.77 (q, 2H, J=7.3); 2.03 (tt, 2H, J-6.4, 7.5); 2.72 (t, 2H, J=7.5); 3.20 (dd, IK, J =4 . 0, 11.8); 3.23 (dd, 1H, J=7.0, 11.8); 4.23 (t, 2H, j=6.4); 4.55 (d, 2H, J-8.9); 5.08 (dd, 1H, J=4.0,. 7-.0); 7.24 (m, 1H) ; 8.48 (m, 2H) . Anal. Calcd. for C19H26N:04S - 0.5 H20: C, 58.89; H, 7.02; N, 7.23. Found: C, 58.83; H, 7.05; N, 7.19. As discussed above, the compounds of the presenc invention have an affinity for the FX5C6 binding protein, particularly FK3P12. The inhibition of the prolyl peptidyi cis-trans isomerase activity of FKB? may be measured as an indicator of this affinity. Ki Test Procedure Inhibition of the peptidyi-prolyl isomerase (rotamase) activity of the inventive compounds can be evaluated by known methods described in the literature (Harding, et al., Nature, 1989, 341:758-760; Holt et al. J". Am. Chem. Soc. , 115:9923-9938). These values are obtained as apparent Ki's and are presented in Table III. The cis-trans isomerization of an alanine-proline bond in a model subscrate, N-succinyi-Ala-Ala-Pro-Phe-p-nitroanilide, is monitored spectrcphccometricaliy in a chymotrypsin-coupled assay, which releases para-nitroanilide from the trans form of the "substrate. The inhibition,._of__this reaction caused fay the addition of different concentrations of inhibitor is determined, and the data is analyzed as a change in first-order rate constant as a function of inhibitor concentration to yield the apparent Ki values. In a plastic cuvette are added 950 mL of ice cold assay buffer (25 mM KEPES, pH 7.8, 100 mM NaCl), 10 mL of FK3? (2.5 mM in 10 mM Tris-Cl pH 7.5, 100 mM NaCl, i mM dithicchreicoi) , 25 mL cf chymotrypsin (50 mg/mi in 1 mM HCI} and 10 mL of test compound at various concentrations in dimethyl suifoxide. The reaction is initiated by the addition of 5 mL cf substrate (succinyl-Ala-Phe-Pro-Phe-para-nitroanilide, 5 mg/mL in 2.35 mM LiCl in trifiucroethanol). The absorbance an 390 nm versus time is monitored for 90 seconds using a spectrophotometer and the rate constants are determined from the absorbance versus time data files. The daca for these experiments for representative compounds are presented in Table III under the column " Ki" . The neurctrophic effects of the compounds of the •• • present: invention can be demonstrated in cellular biological experiments in vitro, as described below. Chick Dorsal Root Ganglion Cultures and Neurite Outgrowth Dorsal root ganglia were dissected from chick embryos of ten day gestation. Whole ganglion explants were cultured' on thin layer Matrigel-coated 12 well plates with Liebcvitz L15 plus high glucose media supplemented with 2 mM glutamine and 10% fetal calf serum, and also containing 10 µM cvtosine S-D arabincfuranoside (Ara C) at 37°C in an environment containing 5% CO.. Twenty-four hours later, the DRGs were treated with various immunophiiin licands. Forty-eight hours after drug treatment, the ganglia were visualized under phase contrast or Hoffman Modulation contrast with a Zeiss Axicvert inverted microsccce. Photomicrographs of the explants were made, and neurite outgrowth was quantitated. Neurites longer than the DRG diameter were counted as positive, with total number of neuritss quantitated per each experimental condition. Three to four DRGs are cultured per well, and each treatment was performed in duplicate. The data for these experiments for representative compounds are presented in the "ED50" column of Table III. Representative photomicrographs of compounds 1. (1 pM, 10 pM, 100 pM) and 2 (10 pM, 100 pM, 10 uM) promoting neurite outgrowth in sensory neurons are shown in FIG.'s 1(A-C) and 2(A-C) , respectively. TABLE El In Vitro Test Results (Table Removed) All publications and.patents identified above are hereby incorporated by reference. The invention being thus described, it will be obvious that the same may be varied- in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention and all such modifications are intended to be included within the scope of the following claims. We claim : 1. A process for preparing a neurotropic low molecular weight heterocyclic compound of formula I (Formula Removed) R2 or a pharmaceutically acceptable salt thereof, wherein: A and B, together with the nitrogen and carbon atoms to which they are respectively attached form a 5-7 membered saturated or unsaturated heterocyclic ring containing at least one additional O, S, SO, SO2 NH or heteroatom in any chemically stable oxidation state; X is O or S; ZisO, NHorNRj; W and Y are independently O; - C1 – C8 straight or branched chain alkyl, which is substituted in one or more position(s) with (Ari)n, - C2 - C6 straight or branched chain alkenyl, which is substituted in one or more positions with (Ari)n, - C3 - C8 cycloalkyl, - C6 — C8 cycloalkyl connected by a C1 - C6 straight or branched chain alkyl or alkenyl, or - Ar2; n is 1 or 2; R2is - C1- C9 straight or branched chain alkyl, . C2 - Cf, straight or branched chain alkenyl, . C3-C8 cycloalkyl, . C5 - C7 cycloalkenyl or - Ar1; wherein said alkyl, alkenyl, cycloalkyl or cycloalkenyl is either unsubstituted or substituted in one or more position(s) with Ci - C4 straight or branched chain alkyl, C2 - C4 straight or branched chain alkenyl, hydroxyl or a combination thereof; and Ari and Ar2 are independently : - a monocyclic carbocyclic ring, - a bicyclic carbocyclic ring - a tricyclic carbocyclic ring, - a monocyclic heterocyclic ring, - a bicyclic heterocyclic ring, or - a tricyclic heterocyclic ring, wherein the ring is either unsubstituted or substituted in one to three positions with - halo, - hydroxyl, - nitro, - triflouromethyl, - Ci - C(y straight or branched chain alkyl or alkenyl, - C2 - C6 straight or branched chain alkyl or alkenyl, - C]-C4alkoxy, - Cj - C4 alkenyloxy, - phenoxy, - benzyloxy, - ammo or - a combination thereof; wherein the individual ring sizes are 5 - 6 members; and wherein the heterocyclic ring contains 1 - 6 heteroatom(s) selected from the group consisting of O, N, S, and a combinaton thereof. which process comprises the steps : (a) reacting in a manner described herein a compound of Formula (la) (Formula Removed) with a compound of formula (Ib): (Formula Removed) wherein A and B are defined above, V is a halogen and R is an alkyl to obtain an intermediate compound of formula (le) wherein RI is H; (Formula Removed) (b): reacting a compound of formula (le) with a compound of formula (Ic): (Formula Removed) wherein Z and R\ are as defined above and (c ) : reacting the product of step (b) with a compound of formula (Id): (Formula Removed) wherein R2 is as defined above to obtain a compound of formula I. 2. A process as claimed in claim 1 wherein the mono- or bicyclic, carbo- or heterocyclic ring is selected from the group consisting of naphthyl, indolyl, furyl, thiazolyl, thienyl, pyridyl, quinolinyl, isoquinolinyl, fluorenyl and phenyl. 3. A process as claimed in claim 1, wherein at least one additional heteroatom in the 5-7 membered saturated or unsaturated heterocyclic ring is S. 4. A process for preparing a neurotrophic low molecular weight, small molecule or a pharmaceutically acceptable salt thereof substantially as herein described with reference to the foregoing examples.

Full Text

I~munophilins were originally discovered and studied
ir. the immune tissue. It was initially postulated by
these skilled in the art that inhibition of the
uncphiiins' rotamase activity leads to inhibition of.
7-ceil proliferation, thereby causing the
immunesuppressive activity exhibited by immunosupcressant
drugs, such as cyclcspcrin A, FX506 and rapamycin.
Further study has shewn that the inhibition of rotamase
activity, in and cf itself, does not result in
i~muncsuppressive activity. Schreiber et al., Science,
1390, vol. 25C, pp. 55c-553. Instead, immunosuppression
appears to stem from the. formulation of a complex of
irnmuncsuppressar.t drugs and irnmuncphilins. It has been
shown that the i-muncphilin-drug complexes interact with
ternary protein targets,, as their mode of action.
Schreiber et al. , Call, 19S1, vol. 56, pp. 807-815. In
the case of FK3F-FK506 and cyclophilin-CsA, the
iT.muncchilin-drug complexes bind to the enzyme
calcineurin and inhibit the T-cell receptor signalling
which leads to T-cell proliferation. Similarly, the
immunophj-lin-drug complex of FK3P-rapamycin interacts
with the RAFT1/FRA? protein and inhibits the IL-2
receptor signalling.
Immunophilins have been found to be present at high concentrations in the central nervous system. Immunochilins are enriched 1.0-50 times more in the
central nervous system tnan in the immune system. Within neural tissues, immunophilins appear to influence nitric oxide synthesis, neurotransmitter release and neurcnal process extension.
It has been found that picomolar concentrations cf an immunosuppressant such as FK5Q6 and rapamycin stimulate neurite outgrowth in PC12 cells and sensory neurons, namely dorsal root ganglion cells (DRGs) . Lyons et al., Proc. of Nad. Acad. Sci., 1994, vol. 91, pp. 3191-3195. In whole animal experiments, FX506 has been shown to stimulate nerve regeneration following facial -nerve injury.'
Surprisingly, it has been found that certain compounds with a high affinity for FKBPs are potent rotamase inhibitors and exhibit excellent neurotrcphic effects. Furthermore, these rotamase inhibitors are devoid of immunosuppressive activity. These findings suggest the use of rotamase inhibitors in treating various peripheral neuropathies and enhancing neuronal regrowth in the central nervous system (CNS). Studies have demonstrated that neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis (ALS) may occur due to the loss, or decreased availability, of a neurotrophic substance specific: for a particular population of neurons affected in the disorder.
Several ' neurotrcphic factors affecting specific neuronai populations in the central nervous system have been identified. For example, it has been hypothesized that Alzheimer's disease results from a decrease or loss of nerve growth factor (NGF). It has thus been proposed to treat SDAT patients with exogenous nerve growth factor or other neurotrophic proteins, such as brain derived growth factor, glial derived growth factor, ciliary neurotrcphic factor and neurotrcpin-3, to increase the survival of degenerating neuronai populations.
Clinical application of these proteins in various neurological disease states is hampered by difficulties in the delivery and bioavailability of large proteins to nervous system targets. By contrast, immunosuppressant drugs with neurotrophic activity are relatively small and display excellent bioavailability and specificity. However, when administered chronically, immunosuppressant drugs exhibit a number of potentially serious side effects including nephrotoxicity, such as impairment of glomerular filtration and irreversible interstitial fibrosis (Kopp et al. , tremors, or non-specific cerebral angina, such as non-localized headaches (De Groen et al., N. Engl. J. Med., 1987, 317:861.); and vascular hypertension with complications resulting therefrom (Kahan et al. , N. Engl.
In order tc prevent the side effects associated with use of the irr.r.unc suppressant compounds, the present invention provides ncn-immunosuppressive compounds containing small molecule FK3P rotamase inhibitors for enhancing neurite outgrowth, and promoting neurcnal growth and regeneration in various neuropathoiogical situations where neuronal repair can be facilitated, including: peripheral nerve damage caused by physical injury or disease state such as diabetes; physical damage to the central nervous system (spinal cord and brain); brain damage, associated with stroke; and neurological disorders relating to neurodegeneration, such as Parkinson's disease, SDA7 (Alzheimer's disease), and amyo.trophic lateral sclerosis.
SUMMARY OF THE INVENTION
The present invention relates tc neurotrophic low molecular weight, small molecule compounds having an affinity for FKB?-type immunophilins. Once bound to these proteins, the neurctrophic compounds are potent inhibitors of the enzyme activity associated with immunophilin proteins, particularly peptidyl-prolyl isomerase, or rctamase, enzyme activity. A key feature of the compounds cf the present invention is that they do not exert any significant immunosuppressive activity in

addition to their neurotropic activity.
Specifically, the present invention relates to a process for preparing a neurotropic low molecular weight heterocyclic compound of formula I
(Formula Removed)
or a pharmaceutically acceptable salt thereof, wherein:
A and B, together with the nitrogen and carbon atoms to which they are respectively attached form a 5-7 membered saturated or unsaturated heterocyclic ring containing at least one additional O, S, SO, SO2 NH or NR] heteroatom in any chemically stable oxidation state; X is O or S; ZisO,NHorNRi; W and Y are independently O; RI is - Ci - Ce straight or branched chain alkyl, which is substituted in one or more
position(s) with (AijX,
- Cz - Ce straight or branched chain alkenyl, which is substituted in one or more positions with (Ar^, €3 - Cg cycloalkyl.,
€3 - Cg cycloalkyl connected by a Q - Cg straight or branched chain alkyl or alkenyl, or
n is 1 or 2;
RI is - Ci - Cg straight or branched chain alkyl,
Ca - Ce straight or branched chain alkenyl, Cs-Cg cycloalkyl, Cs - C? cycloalkenyl or - Ar,;
wherein said alkyl, alkenyl, cycloalkyi or cycloalkenyl is either unsubstituted or substituted in one or more position(s) with Ci - C4 straight or branched chain alkyl, Ca - C4 straight or branched chain alkenyl, hydroxyl or a combination thereof; and
Art and Ar2 are independently : a monocyclic carbocyclic ring, a bicyclic carbocyclic ring a tricyclic carbocyclic ring, a monocyclic heterocyclic ring, a bicyclic heterocyclic ring, or a tricyclic heterocyclic ring,
wherein the ring is either unsubstituted or substituted in one to three positions with halo, hydroxyl, nitro,
triflouromethyl,
Ci - Ce straight or branched chain alkyl or alkenyl, Ca - Ce straight or branched chain alkyl or alkenyl, Ci - C4 alkoxy, Ci - C4 alkenyloxy, phenoxy,
^ - benzyloxy, amino or
a combinationrthereof;
wherein the individual ring sizes are 5-6 members; and wjierein the heterocyclic ring contains 1 - 6 heteroatom(s) selected fi-om the group consisting'bf §, N, S, and a combination thereof.
which process comprises the steps : (a) reacting jn a manner described herein a compound of Formula (la)

(Formula Removed)
wherein A and B are defined above, V is a halogen and R is an alkyl to obtain an intermediate compound of formula (le) wherein Rj is H;

(Formula Removed)
R2 (b): reacting a compound of formula (le) with a compound of formulai(lc):
(Formula Removed)
wherein Z and RI are as defined above and (c ) : reacting the product of step (b) with a compound of formula (Id):
(Formula Removed)
wherein R2 is as defined above to obtain a compound of formula I.
A preferred embodiment of this invention is a compound of formula H:
(Formula Removed)
cr a pharmaceutically acceptable salt thereof, wherein:
A, B and C are independently CH2, 0, S, SO, SO2, NH cr NR,;
RI is C-C5 straight cr branched chain alkyl cr aikenyi, which is substituted in one or more position(s) with (ArJ.,, (Ar:;_ connected by a CX-C6 straight cr branched chain alkyl cr aikenyl, or a combination thereof,-
n is 1 or 2 ;
R2 is either C-CS straight or branched chain alkyi cr aikenyl, C3-C8 cycloalkyl, CS-C7 cycloalkenyl, or Ar^; and
Ar.^ is a mono-, bi- or tricyclic, carbo- cr heterocyclic ring, wherein the ring is either unsubstituted or substituted in one to three position(s) with halo, hydrcxyl, nitro, trifluoromethyl, C-C6 straight or branched chain alkyl or aikenyl, CT-C4 alkoxy, C-C^ alkenylcxy, phenoxy, benzyloxy, amino, or a combination thereof; wherein the individual ring sizes are 5-6 members; and wherein the heterocyclic ring contains 1-6 heteroatom(s) selected from the group consisting of 0, N, S, and a combination thereof.
Another preferred embodiment is a compound of

(Formula Removed)

cr a pharrnaceutically acceptable salt thereof, wherein:
A, B, C and. D are independently CH2, O, S, SO, SO,, NH cr NR;;
R: is C-Cc straight or branched chain alkyl or alkenyi, which is substituted in one or more position(s) with (ArO,, (ArJ. connected by a C-C6 straight or branched chain alkyl cr alkenyi, or a combination thereof;
n is '-. cr^2;
R, is either C-C9 straight or branched chain alkyi or alkenyi., C, -C8 cycioalkyl, C5-C7 cycloalkenyl, or Ar17-and
Ar: is a mono-, bi- or tricyclic, carbo- or heterccyclic ring, wherein the ring is either unsubstituted or substituted in one to three position(s)
with halo, hydroxyl, nitro, trifluoromethyl, Ci-Cg straight or branched chain alkyl or alkenyi, C^-C, alkoxy, C-C, alkenyloxy, phenoxy, benzyloxy, amino, or
a combination thereof; wherein the individual ring sizes
are 5-6 members; and wherein the heterocyclic ring contains' 1-6 heteroatom(s) selected from the grou^ consisting of O, N, S, and a combination thereof.
The present invention aisc relates to a pharmaceutical composition comprising a neurotrophically effective amount of. the compound of formula I, II or III, and a pharrnaceutically acceptable carrier.
The present: invention further relates to a method of effecting a neuronal activity in an animal, comprising:
administering to the animal a neurotrophically effective amount: of the compound of formula I, II or III.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. I (A) is a representative photomicrograph of compound I (1 pM) promoting neurite outgrowth in sensory neurons.
FIG. I(B) is a representative photomicrograph of compound I (10 pM) promoting neurite outgrowth in sensory neurons.
FIG. 1 (C) is a representative photomicrograph of
c
compound 1 (100 pM) promoting neurite outgrowth in sensory neurons.
FIG. 2 (A) is a representative photomicrograph of compound 2 (10 pM) promoting neurite outgrowth in sensory neurons.
FIG. 2(3) is a representative photomicrograph of compound 2 (100 pM) promoting neurite outgrowth in sensory neurons.
FIG. 2(C! is a representative photomicrograph of compound 2 (10 riM) promoting neurite outgrowth in sensorv neurons.
DETAILED DESCRIPTION OF THE INVENTION Definitions
"Alkyl" means a" branched or unbranched saturated hydrocarbon chair, containing 1 to 6 carbon atoms, such as methyl, ethyl, propyl, iso-propyl, "butyl, iso-butyl, tert-butyl, n-pentyl, n-hexyl, and the like, unless otherwise indicated.
"Alkoxy" means the group -OR wherein R is alkyl as herein defined.. Preferably, R is a branched or unbranched saturated hydrocarbon chain containing 1 to 3 carbon atoms.
"Halo" means fluoro, chloro, bromo, or iodc, unless otherwise indicated.
"Phenyl" includes all possible isomeric phenyl radicals, optionally monosubstituted or multi-substituted
with substituents selected from the group consisting of alkyl, alkoxy, hydroxy, halo, and haloalkyl.
The term "pharmaceutically acceptable salt" refers to- salts of t±ie subject compounds which posses the
desired pharmacological activity and which are neither biologically r.cr otherwise undesirable. The salts can be formed with ir.orga.iic acids such as acetate, adipate, aiginate, aspartate, benzoate, benzenesulfonate, bisulfate butyrate, citrate, camphorate, camphorsulfcnate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesuIronate, fumarate, glucoheptancate, glycercphosphate, hemisulfate heptar.oate, hexar.cate, hydrochloride hydrobromide, hydrcicdide, 2-hydroxyethanesulfonate , lactate, maleate, methanesulfcnate, 2-naphthalenesulfonate, nicotinate, oxaiate, thiocyanate, tosylate and undecanoate. Base salts include ammonium salts, alkali metal salts such as sodium and potassium salts, alkaline earth metal salts such as calcium and magne'sium salts, salt with organic bases such as dicyclohexylamine salts, N-methyl-D-glucamine, and salts with amino acids such as arginine, lysine, and so forth. - Also, the basic nitrogen-containing groups can be quartemized with such agents as lower alkyl haiides, such as methyl, ethyl, propyl, and cbutyl chloride, bromides and iodides,-' dialkyl sulfates like dimethyl, diethyl, dibutyl and diamyl sulfates, long chain haiides such as decyl, lauryl, myristyl and stearyl chlorides, bromides and iodides, aralkyl haiides like benzyl and phenethyi bromides and others. Water or oil-soluble or dispersibie products are thereby obtained.
The compounds of this invention possess asymmetric centers and thus can be produced as mixtures of stereoiscmers or as individual stereoisomers. The individual stereoiscmers may be obtained by using an optically ac~ive; starring material, by resolving a racemic or ncn-racemic mixture of an intermediate at some appropriate stage of the synthesis, or by resolution of the compound of formula -, I) . It is understood that the individual stereoiscmers as well as mixtures (racemic and non-racemic) of stereoisomers are encompassed by the scope of the present invention. The compounds of this invention possess at least one asymmetric centers and thus can be produced as mixtures of stereoiscmers or as individual R- and S-s~ereoisomers. The individual enantiomers may be obtained by resolving a racemic or non-racemic mixture of an intermediate at some appropriate stage of the synthesis. It is understood that the individual R- and S- stereoisomers as well as mixtures of stereoisomers are encompassed by this invention. The S-stereoisomer is most preferred due to its greater
c
activity.
"Iscmers" are different compounds that have the same molecular formula.
"Stereoisomers" are isomers that differ only in the way the atoms are arranged in space.
"Enantiomers" are a pair of stersoisomers that are nor.-superimposable mirror images of each ether.
"Diastereoiscmers" are stereoiscmers which are net rr.irrcr images of each ether.
"Racemic mixture" means a mixture containing equal parts of individual enantiomers. "Ncn-racemic mixture" is a mixture containing unequal parts of individual enantiomers or sterecisomers.
The term "treatment" as used herein covers any treatment of a disease and/or condition in an animal, particularly a human, and includes:
(i) preventing a disease and/or condition from occurring in a subject which may be predisposed to the disease and/or condition but has not yet been diagnosed as having it;
•;ii) inhibiting the disease and/or condition, i.e. , arresting its development; or
(iii) relieving the disease and/or condition, i.e. , causing regression of the disease and/or, condition.
The system used in naming the compounds of the present invention is shown below, using a compound of
formula II as an example.
A compound of formula II wherein A is CH2, B is S, C is CH2, RT is 3-phenylpropyl and R2 is 3,3-dimethylpentyl, is named 3-phenyl-l-propyl(2S}-1-(3,3-dimethyl-l, 2-dicxcpencyl) -2- (4-thiazolidine) carboxylate .
Compounds of the Invention
The neurotrophic low molecular weiqht, small molecule FKBP inhibitor compounds of .this invention have an affinity for FKBP-type immunophilins, such as FKBP12. When the neurotrophic compounds of this invention are bound to an ?K3?~type irr.ir.unophilin, they have been found to inhibit the prolyl-peptidyl cis-trans isomerase activity, or rotamase, activity of the binding protein ana unexpectedly stimulate neurite growth.
FORMULA I
In particular, this invention relates to a compound of formula I:
(Formula Removed)

or a pharmaceutically acceptable salt thereof, wherein: A and B, together with the nitrogen and carbon atoms to which they are respectively attached, form a 5-7 membered saturated or unsaturated heterocyclic ring containing, in addition to the nitrogen atom, at least
one additional O, S, SC, SC-, NH or NR, heteroatom in any chemically stable oxidation state,-
X is O or S;
2 is 0, NH or NR-_;
W and Y are independently O, S, CH2 or K2;
R: is C-CS straight or branched chain alkyi or aikenyl, which is substituted in one or more position(s) with 'Ar:}n, (Ar^. connected by a C-CS straight or branched chain aikyl or alkenyi, C3-C3 cycloalkyl, C3-C8 cycloaikyi connected by a C-_-Cs straight or branched chain aikyl or alkenyi, Ar2/ or a corr-bination thereof;
n is 1 or 2;
Rn is either C-C5 straight or branched chain aikyl or aikenyl, C3-CS cycicalkyl, CS-C- cycloalkenyl, or Ar,, wherein said aikyl, -aikenyl, cycloalkyl or cycloalkenyl is either unsubstituted cr substituted in one or more position(s) with C-C4 straight or branched chain aikyl or alkenyi, hydroxyi, cr a combination thereof; and
Ar. and Ar2 are independently a mono-, bi- or tricyciic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted in one to three position(s) with halo, hydroxyi, nitro, trifluoromethyl, C-Cg straight or branched chain aikyl or aikenyl, C^-C^ alkoxy, C-C4 alkenyioxy, phenoxy, benzyloxy, amino, or a combination thereof; wherein the individual ring sizes are 5-6 members; and wherein the heterocyclic ringcontains 1-6 heteroatom(s) selected from the group consisting cf C, N, S, and a combination thereof.
The mcnc- and bicyciic, carbo- and heterocyclic rings include without limitation naphchyl, indolyl, furyl, thiazclyl, chienyl, pyridyl, quinolinyl, iscquinoiinyl, flucrenyl and phenyl.
FORMULA II
A preferred embodiment of this invention is a cornoound of formula II:

(Formula Removed)
cr a pharmaceutically acceptable salt thereof, wherein: A, B and C are independently CH2, O, S, SO, SO2/ NH cr NRI;
RI is Ci-Cc straight or branched chain alkyl or alkenyl, which is substituted in one or more position(s) with (ArJn, (Ar:)n connected by a C^-Cg straight or branched chain alkyl or alkenyl, or a combination thereof;
nisi or .2 ;
R: is either C,-C9 straight or branched chain alkyl cr aikenyl, C,-CS cycloaikyl, CS-C, cycloalkenyl, or Ar, ; and
Ar. is a mono-, bi- cr tricyclic, carbo- or heterccyciic ring, wherein the ring is either unsubstituted cr substituted in one to three position(s) with hale, hydrcxyl, nitre, trifluoromethyl, C-CS straight or branched chain alkyl or aikenyl, C,_-C4 alkcxy, C:-C4 alkenyloxy, phencxy, benzyloxy, amino, or a combination thereof; wherein the individual ring sizes are 5-6 members; and wherein the heterocyclic ring contains 1-6 -heteroatcm(s) selected from the group consisting of C, N, S, and a combination thereof.
In a oarticularly preferred embodiment of formula II compounds:
(Formula Removed)
R, is selected from the group consisting of 3-phenyipropyl and 3 -(3-pyridyi)propyl; and
R2 is selected from the group consisting of 3,3-dimethylpentyi, cyclohexyl, and tert-butyl.
Specific exemplifications of this embodiment are presented in TABUS I.
TABLE I

(Table Removed)
FORMULA III
Another preferred embodiment of this invention is a comoound of formula III:
(Formula Removed)

or a pharmaceutically acceptable salt thereof, wherein: A, B, C and D are independently CH2/ O, S, SO, SO2, NK or NRZ;
j
^ is C-CS straight or branched chain alkyl or alkenyl, which is substituted in one or more position(s)
with (ArO., (Ar,), connected by a C-CS straight or branched chain aikyl cr aikenyl, or a combination thereof;
n is 1 or 2;
R2 is either C-C9 straight or branched chain aikyl or aikenyl, C,-C3 cycioalkyl, C5-CT cycloalkenyl, or Arx; and
Ar1 is a mono-, bi- cr tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted cr substituted in one to three position(s) with halo, hydroxyl, nitro, trifluoromethyl, Q-Cg straig-ht or branched chain aikyl or aikenyl, C,_-C4 alkoxy, C-C4 aikenyloxy, phencxy, benzyloxy, araino, or a combination thereof; wherein the individual ring sizes are 5-6 members; and wherein the heterocyclic ring contains 1-6 .heteroacom(s) selected from the group consisting of 0, N, S, and a combination thereof.
In a particularly preferred embodiment of formula III compounds: A is CK2; B is CH2; C is S, O or NH; D is CH2;
R., is selected from the group consisting of 3-^i am^ /0 , 4 , 5-trimethcxy) phenylpropyl; and

R2 is selected from the group consisting of 3,3-dimethylper.tyl, cyclohexyl, 3-3-dimethylpropyl, phenyl,
and 3,4,5 -trimethoxyphenyl.
Specific exemplifications of this embodiment are cresented in TABLE II.
TABLE
(Table Removed)
The compounds of the present invention exist as stereoisomeric forms, either enantiomers or diasterecisomers. Included within the scope of the invention are the enantiomers, the racemic form, and
c
diastereoiscmeric mixtures. Enantiomers and ddastereois-omers can be separated by methods known to those -skitied
in the art.
Methods of Using the Compounds of the Invention
The compounds of the present invention have an affinity for the FK506 binding protein, particularly FK3PI2, which is present in the brain. When the inventive compounds bind to FK3P in the brain, they exhibit excellent neurotrophic activity. This activity is useful in the stimulation of damaged neurons, the promotion of neuronai regeneration, the prevention of neurodegeneration, and the treatment of several neurological disorders known to be associated with neuronai degeneration and peripheral neuropathies.
For the foregoing reasons, the present invention further relates to a method of effecting a neuronai activity in an animal, comprising.-
administering to the animal a neurotrophically effective amount of a compound of formula I, II or III.
In a preferred embodiment, .the neuronai activity is selected from the group consisting of stimulation of damaged neurons, promotion of neuronai regeneration, prevention of neurodegeneration and treatment of neurological disorder. *
The neurological disorders that may be treated include but are not limited to: trigeminal neuralgia; glossopharyngeal neuralgia; Bell's Palsy; myasthenia gravis,- muscular dystrophy,- amyotrophic lateral sclerosis; progressive muscular atrophy; progressive
bulbar inherited muscular atrophy; hemiated; ruptured or prolapsed invertabrae disk syndromes; cervical spcndylosis,- plexus disorders; thoracic outlet destruction syndromes; peripheral neuropathic such as those caused by lead, dapsone, ticks, porphyria, or Gullain-Barre syndrome; Alzheimer's disease; and Parkinson's disease.
The compounds of the present invention are particularly useful for treating a neurological disorder selected from the group consisting of: peripheral neuropathy caused by physical injury or disease state, physical damage to the brain, physical damage to the spinal cord, stroke associated with brain damage, and neurological disorder relating to neurodegeneration. Examples of neurological disorders relating to neurodegeneration are Alzheimer's Disease, Parkinson's Disease, and amyotrophic lateral sclerosis.
For these purposes the compounds of the present invention may be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an implanted reservoir in dosage formulations - containing conventional non-toxic pharmaceutically-acceptable carriers, adjuvants and vehicles. The term parenteral as used herein includes subcutaneous, intravenous, intramuscular, intraperitoneally, intrathecally, intraventricularly,
intrasternal and intracraniai injection or infusion techniques.
To be effective therapeuticaliy as central nervous system targets, the compounds of the present invention should readily penetrate the blood-brain barrier when peripherally administered. Compounds which cannot penetrate the blood-brain barrier can be effectively administered by an intraventricular route.
The compounds of ..the present invention may be administered in the form of sterile injectable preparations, for example, as sterile injectable aqueous or oleaginous suspensions. These suspensions may be formulated according to techniques known in the art using s.uitable dispersing or wetting agents and suspending
-! |f
agents. The sterile injectable preparations may also be sterile injectable solutions or suspensions in non-toxic parenteraliy-acceptable diluents or solvents, for example, as solutions in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride
c
solution. .In addition, sterile, fixed oils are conventionally employed as solvents or suspending mediums. For. this purpose, any bland fixed oil may be employed including synthetic mono- or di-glycerides. Fatty acids such as oleic acid and its glyceride derivatives, including olive oil and castor oil,
especially in their polyoxyethylated versions, are useful in the preparation of injectables. These-oil solutions or suspensions ~ay also contain long-chain alcohol diluents or dispersa-nts .
The compounds may be administered orally in the form of capsules, tablets, aqueous suspensions or solutions. Tablets may contain carriers such as lactose and corn starch, and/or lubricating, agents such as magnesium stearate. Capsules may contain diluents including lactose and dried corn starch. Aqueous suspensions may contain emulsifying and suspending agents combined with the active ingredient. The oral dosage forms may further contain sweetening and/or flavoring and/or coloring agents.
The compounds of this invention may also be administered rsctaliy in the form of suppositories. These compositions can be prepared by mixing the drug with a suitable non-irritating excipient which is solid at room temperature, but liquid at rectal temperature and, therefore, will melt in the rectum to release the drug. Such materials "include cocoa butter, beeswax and polyethylene glycols.
The compounds of this invention may also be administered topically, especially when the conditions addressed for treatment involve areas or organs readily accessible by topical application, including
neurological disorders of the eye, the skin, or the lower intestinal tract. Suitable topical formulations are readily prepared for each of these areas.
For topical application to the eye, or ophthalmic use, the compounds can be formulated as micronized suspensions in isotcnic, pH adjusted sterile saline, or, preferably, as solutions in isctonic, pH adjusted sterile saline, either with or without a preservative such as benzyialkonium chloride. Alternatively for the ophthalmic uses the compounds may be formulated in an ointment such as petrolatum.
For topical application to the skin, the compounds can be formulated in a suitable ointment containing the compound suspended or dissolved in, for example, a mixture with one or more of the following: mineral oil, liquid petrolatum, white petrolatum, propylene giycol, polyoxyethylene polyoxypropylene compound, emulsifying wax and water. Alternatively, the compounds can be formulated in a suitable lotion or cream containing the active compound suspended or dissolved in, for example,
c
a mixture of one or more of the following: mineral oil, sorbitan monostearate, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water.
Topical application for the lower intestinal tract an"be-effected. iri a rectal suppository formulation (see
above) cr in a suitable enema formulation.
Dcsage levels on the order cf about 0.1 mg to about 10,COO mg cf the active ingredient compound are useful in the treatment of the above conditions, with preferred levels cf about 0.1 mg to about 1,000 mg. The amount of active ingredient that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration.
It is understood, however, that a specific dose level for any particular patient will depend upon a variety cf factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time cf administration, rate of excretion, drug combination, and the severity of the particular disease being treated and form cf administration.
The compounds can be administered with other neurctrophic agents such as neurctrophic growth factor (NG?), giial derived growth factor, brain derived growth factor, ciliary neurotrophic factor, and neurotropin-3.
c
The dosage level of other neurotrophic drugs will depend upon the factors previously stated and the neurotrophic effectiveness of the drug combination.

Pharmaceutical: Compositions of the Invention
The present: invention also relates to a pharmaceutical composition comprising:
(i) a neurotrophically effective amount of the compound of formula I, II or III, and
(ii) a pharmaceutically acceptable carrier.
The above discussion relating to the utility and administration of the compounds of the present invention also applies to the pharmaceutical compositions of the present invention.
Examples
The following examples are illustrative of the present invention and are not intended to be limitations thereon. Unless otherwise specified, all percentages are based on 100% by weight of the final compound.
EXAMPLE 1
Synthesis of 3-phenyl-l-.pr.opyl (2S) -1- (3 , 3-d-imethvl-1, 2-dioxopentyl) -2- (4-thia2olidine) carboxvlate {1)
•«
1- (1, 2 -dioxo-2 -me-thoxve.thvl) 2 - (4 -thiazolidine) -carboxylate. A solution of L-thioproline (1.51 g; 11.34 mmol) in 40 mL of dry methylene chloride was cooled to 0°C and treated with 3.3 mL (2.41 g; 23,81 mmol) of
*
triethylamine.' After stirring this mixture for 30 minutes, a solution of methyl oxalyl chloride (1.81 g;
14.74 mmol) was added dropwise. The resulting mixture was stirred at 0°C for 1.5 hours, filtered through Celite to remove solids, dried and concentrated. The crude material was purified on a silic gel column, eluting with 10% MeCH in methylene chloride, to obtain 2.0 g of the cxamate as an orange-yellow solid.
3 -chenvl-1 -proovl (253 -1 - (1, 2 -dioxo-2-methoxyethyl) 2 -(4 -thiazolidine)carboxvlate. 1- (1,2-dioxo-2 -rnethcxyethyi) 2- (4-thiazolidine) carboxylate (500 mg; 2.25 mmol}, 3-phenyl-1-propanol (465 mg; 3.42 mmol), dicyciohexylcarbodiimide • (750 mg; 3.65 mmol), 4-dimethyiamincpyridine (95 mg; 0.75 mmol) and camphcrsulfcnic acid (175 mg; 0.75 mmol) in 30 mL of methylene chloride were stirred together overnight. The mixture was filtered through Celite to remove solids" and chromatcgrapheg (25% ethyl acetane/hexane) to obtain 690 mg of material, ZH NMR (CDC13, 300 MHz) : 51.92-2.01 (m, 2H); 2.61-2.69 (m, 2H); 3-34 (m, 1H) ; 4.11-4.25 (m, 2H); 4.73 (m, IK); 5.34 (m, 1H) ; 7.12 (m, 3H) ; 7.23 (m, 2H)„
3 - ohe nv 1 - 1 - P r.op v 1 (25? - 1 - (3 , 3 - d i me t hy 1 - 1 , 2 -dioxopentvl)-2-(4-thiazolidine)carboxvlate (1) . A solution of 3-phenyl-l-prcpyl(25)-1-(1,2-dioxo-2-
methoxyethyl) 2-(4-thiazolidine) carboxylate (670 mg; 1.98 mmol) in tetrahydrofuran (10 mL) was cooled to -78°C and treated with 2.3 mL of a 1.0 M solution of 1,1-dimethylpropylmagnesium chloride in ether. After
stirring the mixture for 3 hours, it was poured into saturated ammonium chloride, extracted into ethyl acetate, and the organic phase was washed with water, dried and concentrated. The crude material was purified on a silica gel colun^n, eiuting with 25% ethyl acetate in hexane, to obtain 3SG mg of the compound of Example 1 as a yellow oil, LK NMR (CDC1,, 300 iMHz) : d 0.86 (t, 3H) ; 1.21 (s, 3H); 1.26 is, 3H); 1.S2-1.91 (m, 3H); 2.01 (m, 2K) ; 2.71 (m/ 2K) ; 2.26-3.23 (m, 2K) ; 4.19 (m, 2K) ; 4.58 (m, IK); 7.19 (m, 3H) ; 7.30 (m, 2H) . Anal. Clcd. for C20H27NC.S: C, 63.63; H, 7.23; N, 3.71. Found: C, 64.29; H, 7.35; N, 3.46.
EXAMPLE 2 Synthesis of 3 - (3-pyridyl) -1-propvl (23} -.1- (3/3 -dimethyl-
1, 2-dioxopentvl) -2- (4-thiazolidine) ^carboxylaite {2}
*-
The compound of Example 2 was prepared according to the procedure of Example 1, using 3 -(3-pyridyl)-1-propancl in the final step, to yield 3-(3-pyridyl)-1-propyi(25) -1- (3 , 3-dimethyl -1,2-dioxopentyl) -2 - (4-thiazolidine) carboxy late,. -H NMR (CDC13, 300 MHz):- 6 0.89 (t, 3H, J=7.3); 1.25 (s, 3H) ; 1.28 (s, 3H) ; 1.77 (q, 2H, J=7.3); 2.03 (tt, 2H, J-6.4, 7.5); 2.72 (t, 2H, J=7.5); 3.20 (dd, IK, J =4 . 0, 11.8); 3.23 (dd, 1H, J=7.0, 11.8); 4.23 (t, 2H, j=6.4); 4.55 (d, 2H, J-8.9); 5.08 (dd, 1H, J=4.0,. 7-.0); 7.24 (m, 1H) ; 8.48 (m, 2H) . Anal.
Calcd. for C19H26N:04S - 0.5 H20: C, 58.89; H, 7.02; N, 7.23. Found: C, 58.83; H, 7.05; N, 7.19.
As discussed above, the compounds of the presenc invention have an affinity for the FX5C6 binding protein, particularly FK3P12. The inhibition of the prolyl peptidyi cis-trans isomerase activity of FKB? may be measured as an indicator of this affinity.
Ki Test Procedure
Inhibition of the peptidyi-prolyl isomerase (rotamase) activity of the inventive compounds can be evaluated by known methods described in the literature (Harding, et al., Nature, 1989, 341:758-760; Holt et al. J". Am. Chem. Soc. , 115:9923-9938). These values are obtained as apparent Ki's and are presented in Table III. The cis-trans isomerization of an alanine-proline bond in a model subscrate, N-succinyi-Ala-Ala-Pro-Phe-p-nitroanilide, is monitored spectrcphccometricaliy in a chymotrypsin-coupled assay, which releases para-nitroanilide from the trans form of the "substrate. The inhibition,._of__this reaction caused fay the addition of different concentrations of inhibitor is determined, and the data is analyzed as a change in first-order rate constant as a function of inhibitor concentration to yield the apparent Ki values.
In a plastic cuvette are added 950 mL of ice cold assay buffer (25 mM KEPES, pH 7.8, 100 mM NaCl), 10 mL of FK3? (2.5 mM in 10 mM Tris-Cl pH 7.5, 100 mM NaCl, i mM dithicchreicoi) , 25 mL cf chymotrypsin (50 mg/mi in 1 mM HCI} and 10 mL of test compound at various concentrations in dimethyl suifoxide. The reaction is initiated by the addition of 5 mL cf substrate (succinyl-Ala-Phe-Pro-Phe-para-nitroanilide, 5 mg/mL in 2.35 mM LiCl in trifiucroethanol).
The absorbance an 390 nm versus time is monitored for 90 seconds using a spectrophotometer and the rate constants are determined from the absorbance versus time data files.
The daca for these experiments for representative compounds are presented in Table III under the column " Ki" .
The neurctrophic effects of the compounds of the
••* •
present: invention can be demonstrated in cellular biological experiments in vitro, as described below.
Chick Dorsal Root Ganglion Cultures and Neurite Outgrowth
Dorsal root ganglia were dissected from chick embryos of ten day gestation. Whole ganglion explants were cultured' on thin layer Matrigel-coated 12 well plates with Liebcvitz L15 plus high glucose media
supplemented with 2 mM glutamine and 10% fetal calf serum, and also containing 10 µM cvtosine S-D arabincfuranoside (Ara C) at 37°C in an environment containing 5% CO.. Twenty-four hours later, the DRGs were treated with various immunophiiin licands. Forty-eight hours after drug treatment, the ganglia were visualized under phase contrast or Hoffman Modulation contrast with a Zeiss Axicvert inverted microsccce. Photomicrographs of the explants were made, and neurite outgrowth was quantitated. Neurites longer than the DRG diameter were counted as positive, with total number of neuritss quantitated per each experimental condition. Three to four DRGs are cultured per well, and each treatment was performed in duplicate.
The data for these experiments for representative compounds are presented in the "ED50" column of Table III. Representative photomicrographs of compounds 1. (1 pM, 10 pM, 100 pM) and 2 (10 pM, 100 pM, 10 uM) promoting neurite outgrowth in sensory neurons are shown in FIG.'s 1(A-C) and 2(A-C) , respectively.
TABLE El
In Vitro Test Results
(Table Removed)

All publications and.patents identified above are hereby incorporated by reference.
The invention being thus described, it will be obvious that the same may be varied- in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention and all such modifications are intended to be included within the scope of the following claims.

We claim :
1. A process for preparing a neurotropic low molecular weight heterocyclic compound of formula I
(Formula Removed)
R2 or a pharmaceutically acceptable salt thereof,
wherein:
A and B, together with the nitrogen and carbon atoms to which they are respectively attached form a 5-7 membered saturated or unsaturated heterocyclic ring containing at least one additional O, S, SO, SO2 NH or heteroatom in any chemically stable oxidation state;
X is O or S;
ZisO, NHorNRj;
W and Y are independently O;
- C1 – C8 straight or branched chain alkyl, which is substituted in
one or more position(s) with (Ari)n,
- C2 - C6 straight or branched chain alkenyl, which is substituted
in one or more positions with (Ari)n,
- C3 - C8 cycloalkyl,
- C6 — C8 cycloalkyl connected by a C1 - C6 straight or branched
chain alkyl or alkenyl, or
- Ar2;
n is 1 or 2;
R2is
- C1- C9 straight or branched chain alkyl,
. C2 - Cf, straight or branched chain alkenyl,
. C3-C8 cycloalkyl,
. C5 - C7 cycloalkenyl or
- Ar1;
wherein said alkyl, alkenyl, cycloalkyl or cycloalkenyl is either unsubstituted or substituted in one or more position(s) with Ci - C4 straight or branched chain alkyl, C2 - C4 straight or branched chain alkenyl, hydroxyl or a combination thereof; and Ari and Ar2 are independently :
- a monocyclic carbocyclic ring,
- a bicyclic carbocyclic ring
- a tricyclic carbocyclic ring,
- a monocyclic heterocyclic ring,
- a bicyclic heterocyclic ring, or
- a tricyclic heterocyclic ring,
wherein the ring is either unsubstituted or substituted in one to three positions with
- halo,
- hydroxyl,
- nitro,
- triflouromethyl,
- Ci - C(y straight or branched chain alkyl or alkenyl,
- C2 - C6 straight or branched chain alkyl or alkenyl,
- C]-C4alkoxy,
- Cj - C4 alkenyloxy,
- phenoxy,
- benzyloxy,
- ammo or
- a combination thereof;
wherein the individual ring sizes are 5 - 6 members; and wherein the heterocyclic ring contains 1 - 6 heteroatom(s) selected from the group consisting of O, N, S, and a combinaton thereof.
which process comprises the steps :
(a) reacting in a manner described herein a compound of Formula (la)
(Formula Removed)
with a compound of formula (Ib):
(Formula Removed)
wherein A and B are defined above, V is a halogen and R is an alkyl to obtain an intermediate compound of formula (le) wherein RI is H;
(Formula Removed)
(b): reacting a compound of formula (le) with a compound of formula (Ic):
(Formula Removed)
wherein Z and R\ are as defined above and
(c ) : reacting the product of step (b) with a compound of formula (Id):
(Formula Removed)
wherein R2 is as defined above to obtain a compound of formula I.
2. A process as claimed in claim 1 wherein the mono- or bicyclic, carbo- or
heterocyclic ring is selected from the group consisting of naphthyl, indolyl,
furyl, thiazolyl, thienyl, pyridyl, quinolinyl, isoquinolinyl, fluorenyl and phenyl.
3. A process as claimed in claim 1, wherein at least one additional heteroatom
in the 5-7 membered saturated or unsaturated heterocyclic ring is S.
4. A process for preparing a neurotrophic low molecular weight, small
molecule or a pharmaceutically acceptable salt thereof substantially as herein
described with reference to the foregoing examples.

Documents:

2420-del-1997-abstract.pdf

2420-del-1997-claims.pdf

2420-del-1997-complete specification (granted).pdf

2420-del-1997-correspondence-others.pdf

2420-del-1997-correspondence-po.pdf

2420-del-1997-description (complete).pdf

2420-del-1997-drawings.pdf

2420-del-1997-form-1.pdf

2420-del-1997-form-2.pdf

2420-del-1997-form-3.pdf

2420-del-1997-form-4.pdf

2420-del-1997-form-5.pdf

2420-del-1997-form-6.pdf

2420-del-1997-pa.pdf

2420-del-1997-petition-138.pdf

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Patent Number

213810

Indian Patent Application Number

2420/DEL/1997

PG Journal Number

38/2008

Publication Date

19-Sep-2008

Grant Date

17-Jan-2008

Date of Filing

27-Aug-1997

Name of Patentee

GUILFORD PHARMACEUTICALS INC.

Applicant Address

DELAWARE,BALTIMORE, MARYLAND 21224, U.S.A.

Inventors:

#	Inventor's Name	Inventor's Address
1	GREGORY SCOTT HAMILTON	6501 FREDERICK ROAD, CATONSVILLE, MARYLAND 21228, U.S.A.
2	LI-HE-LI	27 WARREN MANOR COURT COCKEYSVILLE, MARYLAND 21030, U.S.A.

PCT International Classification Number

A61K 31/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	08/719,947	1996-09-25	U.S.A.